High repetition rate diode pumped thin disk laser of the Joule class

A diode pumped CPA laser system based on Yb:YAG thin disk technology has been developed. This system delivers picosecond pulses with energy up to the Joule level at a repetition rate of 100 Hz. It consists of a front-end, a CPA grating stretcher and compressor, and a chain of thin disk amplifiers. Pulse energy of more than 150 mJ, pulse duration below 2 ps, and a maximum repetition rate of 100 Hz is demonstrated. The laser system shows a high stability of better than 0.8% (rms) measured over a period of 45 min and an excellent beam quality with M2 better than 1.2. The oscillator pulse is stretched from 150 fs to 2 ns and amplified to a pulse energy of 1 mJ. After the stretcher a pre-amplifier consisting of a regenerative amplifier and multipass amplifier both based on thin disk technology amplifies the pulse energy to 150 mJ and 300 mJ. A booster-amplifier as last stage amplifies the pulse up to the Joule level. Due to gain narrowing the spectral bandwidth is reduced to about 1.5 nm. Pulses amplified in RA of the pre-amplifier could be (nearly bandwidth limited) re-compressed to less than 2 ps.